English (GB)
5
7. Operating conditions
7.1 Temperatures
7.1.1 Ambient temperature during storage and transportation
Minimum -30 °C
M60 °C.
7.1.2 Ambient temperature during operation
Minimum -20 °C
M50 °C.
The motors can operate with the rated output power (P2) at 50
°C, but continuous operation at higher temperatures will reduce
the expected product life. If the motors are to operate at ambient
temperatures between 50 and 60 °C, oversized motors must be
selected. Contact Grundfos for further information.
7.1.3 Liquid temperature
0 to +60 °C.
7.2 Installation altitude
Installation altitude is the height above sea level of the installation
site.
• Motors installed up to 1000 metres above sea level can be
loaded 100 %.
• Motors installed more than 1000 metres above sea level must
not be fully loaded due to the low density and consequent low
cooling effect of the air. See fig.
Fig. 3
Derating of motor output power (P2) in relation to
altitude above sea level
7.3 Relative humidity
Maximum 95 %.
7.4 Maximum operating pressure
See system nameplate.
7.5 Shaft seal run-in
The seal faces are lubricated by the pumped liquid, meaning that
there may be a certain amount of leakage from the shaft seal.
When the pump is started up for the first time, or when a new
shaft seal is installed, a certain run-in period is required before
the leakage is reduced to an acceptable level. The time required
for this depends on the operating conditions, that is every time
the operating conditions change, a new run-in period will be
started.
Under normal conditions, the leaking liquid evaporates. As a
result, a leakage will not be detected.
7.6 Minimum inlet pressure
Fig. 4
Parameters for the calculation of minimum inlet
pressure
The minimum inlet pressure "H" in metres head required to avoid
cavitation in the pumps can be calculated as follows:
Hydro Multi-E with CME pumps
Hydro Multi-E systems with CME pumps always require a positive
inlet pressure, both during startup and operation.
Do not install the motors more than 2000 metres
above sea level.
T
M
05
64
00
47
1
2
1
0.99
0.98
0.97
0.96
0.95
0.94
0.93
0.92
0.91
0.90
0.89
0.88
0
0
1000
1200
1400
1600
1800
2000 2200
[m]
P2
[%]
Altitude [m]
P2
[%]
TM
02 01
18
38
00
H
= pb x 10.2 - NPSH - Hf - Hv - Hs
pb
= Barometric pressure in bar. Barometric pressure can
be set to 1 bar.
In closed systems, p
b
indicates the system pressure in
bar.
NPSH = Net Positive Suction Head in metres head
The NPSH value can be read from the NPSH curve at
the highest flow which the individual pump will be
delivering.
Hf
= Friction loss in inlet manifold in metres head at the
highest flow the individual pump will be delivering.
Note:
If a non-return valve is installed on the inlet side
of the pump, the friction loss in the valve must be
added. See the manufacturer's data.
Hv
= Vapour pressure in metres head.
Hs
= Safety margin of min. 0.5 metres head.
In some regions, the booster system is available with
a low inlet manifold which makes it more suitable for
suction lift operation. Contact Grundfos for further
information.
Hv
H
NPSH
Pb
Hf
Hf
H
pb
Hv
NPSH
